1. Field
One or more embodiments described herein relate to a battery pack.
2. Description of the Related Art
A battery pack includes a control circuit for controlling a plurality of secondary cells. The secondary cells may convert chemical energy to electrical energy, or vice versa, and may be repeatedly charged and discharged. The control circuit may be driven by an external power source connected to an external terminal of the battery pack.
When no external power source is connected to the battery pack, the control circuit may receive power from the secondary cells. When the secondary cells are in a low-voltage state, the control circuit turns on switches between the secondary cells and the external terminal in order to protect the cells.
However, the secondary cells continuously supply power to the control circuit. Accordingly, the secondary cells continue to be discharged in a low-voltage state. This may shorten the lifetime of the battery pack and needlessly reduce battery charge.